18V 1.6A electrolysis of 2 cupronickel coins (25% Ni) in 33% HCl probably less it was extremely old and had visible white flakes in it. a coin was
used for both electrodes. the negative terminal would bubble like crazy if both the electrodes were just barely submerged and an orange spongey mass
would accumulate on the cathode however not much bubbling was seen at all if both were submerged fully. was wondering what this orange mass is as
theres alot of it my guess is copper (I) oxide but after it breaks off it would accumulate in the bottom of the vessel and not dissolve?
not a major concern just curious as the anode dissolves fine however to obtain the nickel couldn't one treat the final solution with NaOH then boil to
decompose the copper to the oxide and treat with hydrogen gas (Al + HCl or NaOH) to make copper metal and then add acetic acid to make nickel acetate
and separate via filtration? im sketchy at what temp is required to make the H2 eat the oxide and wether this is best done in solution or to the dried
metal salts or even possible at all. this is all plain curiosity as pure nickel guitar strings are another option.
[Edited on 23-4-2011 by caliber]cyanureeves - 23-4-2011 at 13:00
sounds good to me,try it! you'll probably be routed over to the extraction of nickel from cupronickel thread.most of the copper will go to the
cathode.i said try it because even the other thread has alot of theories that are not followed through all the way or have not been reported.ammonium
hydroxide has been tried but both copper and nickel form complexes.i'm trying nichrome but gave up as i think it has alot of iron so i'm trying the
method plante1999 used to at least isolate some chromium and hopefully a nit of nickel in solution.i've tried using salicylic acid acid to make
coppersalicylic and liberate the nickel but seem to just get a purple coppernickel compound. i tried the carbonate but both nickel and copper went
into carbonation.bubbling hydrogen through your solution will precipitate copper metal?just pure curiosity here too.caliber - 23-4-2011 at 13:50
well the idea is once u have your chlorides in solution treat it with NaOH to get the hydroxides however Cu(OH)2 will decompose (only in the presence
of water) at 80C to CuO. so we have a solution of CuO and Ni(OH)2 from what i know H2 will turn the CuO back into Cu but wether this can simply be
done in situ (80-100C) is the question. one might have to evaporate the water and heat to a much higher temperature for this to work which could
complicate things. ive had just about enough google/search engine for today so im leaving it at that for now but i did see a video where they
blowtorched the crap outa a piece of copper and passed hydrogen gas over it straight after which turned the blackened mass orange coloured again
almost instantly. it seems promising caliber - 23-4-2011 at 23:34
according to the above pdf the copper oxide will completely reduce regardless of particle size if just above 200C and 2L/min of H2. decomposition of
Ni(OH)2 occurs at 230C so the alternative is simply ensuring the H2 is dry this allows for a temperature of 148C with a time of 102 minutes. its hard
to say what effect the nickel hydroxide would have in the reaction but the finer the particle size the better most probably. the data suggests that
the initial formation of the hydroxides and later oxide would probably be the biggest determining factor of success and time required. may be
neccessary to recrystalize the final Ni(OH)2 after the reduction of the oxide and run the reaction again to clean up any trapped copper oxide left
over.
a theoretical 204L of H2 gas is required at the most. thats 18.34g of H2 which is just over 9 moles (not sure if thats correct). anyone proficient in
H2 generators that can say wether thats a mission to venus? things like steel vessels to allow H2 pressure and playing with the oxide prep and
temperature would significantly reduce the H2 necessary.
those nickel guitar strings are starting to sound pretty nice right about now.bbartlog - 24-4-2011 at 13:18
I looked at the temperature difference (for decomposition to the oxide) as a way of separating Ni and Cu as well, but I don't think it's all that
promising. First of all, you will probably not achieve perfect decomposition of Cu(OH)2 before the Ni(OH)2 also starts decomposing. That's minor
though. More importantly, you end up with a mixture of CuO and Ni(OH)2 (not a solution, these are not normally soluble in water), and still have more
or less the same separation problem as before. Adding acid to dissolve either will generally dissolve both; likewise adding base will not dissolve one
without the other, barring something exotic.
Now if you can reduce the copper with hydrogen without touching the Ni(OH)2, that changes things - but I don't think the reaction proceeds at a
reasonable rate at temperatures that will leave the Ni(OH)2 untouched.caliber - 25-4-2011 at 20:06
what temperature does nickel hydroxide decompose in solution? only temp i could find was its anhydrous decomp temp which was 230C.caliber - 26-4-2011 at 04:48
"in solution" I've been using that a fair bit i know the hydroxides don't dissolve in H2O i just mean the compound is a precipitate inside an aqueous
solution.Neil - 3-5-2011 at 20:46
With regards to cupronickle, you may want to look up the metal Monel and compare the properties.
If you are after Nickle why not purchase the pottery oxide, or carbonate and ether start from that point, or reduce it to a metal and dissolve the
purish metal?
I'd suggest that if the anhydric degrades at 230°C the answer would be it does not degrade in 'solution' as in 'in water', unless you can make 230°C
dry water at one atmosphere(If you calculate the mol's of your reactants and divide them by 0 you might just get the correct conditions for this
reaction). you can not get it to the anhydrous (an - without and hydrous-water so "without water") state if it is in water.
If you are heating the reactants to 200°C and passing hydrogen over them, they would have to be dry see below. (remember water boils at 100°C)
From the posted link
"Water vapor in concentrations of 25 mg per liter of hydrogen prevented reduction at 112OC. The inhibiting effect decreased rapidly as the
temperature was increased and disappeared entirely at 190'C. Once reduction had started, water vapor had practically no effect."
anyone proficient in H2 generators that can say wether thats a mission to venus? things like steel vessels to allow H2 pressure and playing with the
oxide prep and temperature would significantly reduce the H2 necessary.
I am not proficient in reacting hydrogen with metal oxides at high heats and pressures because it is a trip to Venus, if you get my drift.
[Edited on 4-5-2011 by Neil]cyanureeves - 4-5-2011 at 12:04
in my case i have some nickel salt and nickel oxide can be turned to nickel acetate fairly quickly and nickel acetate can plate from a cold solution
very nicely. nickel oxide price is high and i always look at cupronickel's abundance yet so difficult to separate. i personally would be thrilled with
nickel whatever,sulfate.chloide.nitrate,carbonate etc.. as long as it is in a pure enough form.. caliber and bartlog talk of degrees,decomposition and
pressure is all N.A.S.A. to me. i'm just a mackeral swimming among big sharks until i get bit.
